1. Field of the Invention
The present invention relates to a smart meter, and more particularly, to a smart meter with wireless transmission capability.
2. Description of the Prior Art
A traditional electric meter is usually installed at the first floor of a residential building, for measuring an amount of electricity consumed by residents. The electric meter also provides related power consumption information, e.g., an amount of consumed energy in kilowatt-hours, to a power company or the residents for reference. The power consumption information needs to be transcribed by staffs of the power company, which may lead to man-made errors. Meanwhile, manual transcriptions are inefficient, and waste both time and effort. As the rapid evolution of technologies, the traditional meters are gradually replaced by smart meters.
Smart meters not merely overcome drawbacks of manual transcription brought by traditional electric meters, some types of smart meters even provide information to residents such that they can analyze their behaviors of electrical power consumption and further modify their behavior so as to save energy. Furthermore, some types of smart meters are equipped with functionality for recognizing electrical equipment statuses, which may perform loading recognition according to power information provided by electrical meters, and combine environment information provided by sensors and electrical control capability provided by actuators, for designing various customized applications, and realizing smart life model in the future.
Since wireless modules need different size of antennas, in order to transmit signals in different frequency bands, such as GSM/CDMA signals, ZigBee signals, Wifi signals, and even LTE signals, traditional smart meters usually have multiple transmission devices inside, meaning that multiple antennas are needed to deal with signals in multiple frequency bands. Hence, more space is occupied by the antennas, and interference is more complicate and serious.